Communication device and communication method

ABSTRACT

The present disclosure relates to a communication device and a communication method. The communication device according to one embodiment comprises an acquisition unit, a determining unit, and a trigger unit. The acquisition unit is configured to acquire distribution information of user devices in a dynamic network, said user devices at least comprising a slave device, the slave device in device-to-device communication acquiring a communication service by means of a master device. The determined unit is configured to determining a re-configuration method of the dynamic network on the basis of the acquired information. The trigger unit is configured to trigger the re-configuration of the dynamic network on the basis of the determined method.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of U.S. application Ser. No.15/544,437, filed Jul. 18, 2017, which is based on PCT filingPCT/CN2016/072119, filed Jan. 26, 2016, which claims priority to CN201510050840.3, filed Jan. 30, 2015, the entire contents of each areincorporated herein by reference.

FIELD

The present disclosure relates to the field of communication, and moreparticularly, to a communication device for a dynamic network and acommunication method performed by the communication device.

BACKGROUND

With rapid development of the computer and communication technology, thenumbers of user equipments, service requirements and usage scenariosincrease exponentially, thereby further intensifying a contradictionbetween wireless service requirements and wireless spectrum resources. Adynamic network tries to ensure effective utilizing of the resourceswhile satisfying a user requirement by continuously adjust a networkconfiguration (including function of network node and data transmissionpath and so on) during a network operation process thereby furtherexploit reusing efficiency of the radio resource.

SUMMARY

One characteristic of a dynamic network is to support diversity andvariability of access terminals and mobile user equipments. In aconventional network management method, movement, power, change ofswitch state or the like of a mobile user equipment can not be trackedquickly according to channel quality measurement and feedback of themobile user, therefore it is difficult to timely response to a rapidlychanging network state, and thus it may result in that the mobile usercan not obtain a stable access and service, thereby influencing aspectrum utilization and a system capacity of a whole network.

Brief summary of embodiments of the present disclosure is givenhereinafter, to provide basic understanding for certain aspects of thepresent disclosure. It should be understood that, the summary is notexhaustive summary of the present disclosure. The summary is notintended to determine key parts or important parts of the presentdisclosure, and is not intended to limit the scope of the presentdisclosure. The object of the summary is only to give some concepts ofthe present disclosure in a simplified form, as a preamble of thedetailed description later.

According to an embodiment, a communication device is provided. Thecommunication device includes an acquiring unit, a determining unit anda triggering unit. The acquiring unit is configured to acquireinformation on distribution of user equipments in a dynamic network,where the user equipments include at least a slave device which obtainsa communication service via a master device during a device-to-devicecommunication. The determining unit is configured to determine areconfiguration scheme of the dynamic network according to the acquiredinformation. The triggering unit is configured to trigger areconfiguration to be performed on the dynamic network according to thedetermined scheme.

According to another embodiment, a communication method performed by acommunication device is provided. The method includes: acquiringinformation on distribution of user equipments in a dynamic network,where the user equipments include at least a slave device which obtainsa communication service via a master device during a device-to-devicecommunication; determining a reconfiguration scheme of the dynamicnetwork according to the acquired information; and triggering areconfiguration to be performed on the dynamic network according to thedetermined scheme.

According to yet another embodiment, a communication device for userside is provided. The communication device includes a receiving unit anda transmitting unit. The receiving unit is configured to receive atransmitting request from a user equipment or a network infrastructure.The transmitting unit is configured to transmit, in response to thetransmitting request, a reference signal for determining thedistribution of the communication device in a dynamic network in a casewhere the communication device does not serve as a slave device whichobtains a communication service via a master device during adevice-to-device communication.

According to still another embodiment, a communication method performedby a communication device is provided. The method includes receiving atransmitting request from a user equipment or a network infrastructure.In addition, the method further includes transmitting, in response tothe transmitting request, a reference signal for determining thedistribution of the communication device in a dynamic network in a casewhere the communication device does not serve as a slave device whichobtains a communication service via a master device during adevice-to-device communication.

According to the embodiment of the present disclosure, a reconfigurationon a dynamic network containing a device-to-device communication isdetermined and triggered according to the distribution of userequipments in the dynamic network, thereby being beneficial for ensuringa stability of a user access link and improving a spectrum utilizationof a network and a system capacity.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure may be understood better with reference to thedescription given in conjunction with drawings hereinafter. Same orsimilar reference numerals are used to indicate the same or similarcomponents throughout the drawings. The drawings, together with thefollowing detailed description are included in the specification, form apart of the specification, and are used to further illustrate preferredembodiments of the present disclosure and explain principles andadvantages of the present disclosure by examples. In the drawings:

FIG. 1 is a block diagram of a configuration example of a communicationdevice according to an embodiment of the present disclosure;

FIG. 2 is a schematic diagram of an example of a communication system towhich an embodiment of the present disclosure may be applied;

FIG. 3 is a schematic diagram of an exemplary process according to anembodiment of the present disclosure;

FIG. 4 is a schematic diagram of another exemplary process according toan embodiment of the present disclosure;

FIG. 5 is a schematic diagram of yet another exemplary process accordingto an embodiment of the present disclosure;

FIG. 6 is a block diagram of a configuration example of a communicationdevice according to another embodiment of the present disclosure;

FIG. 7 is a block diagram of a configuration example of a communicationdevice according to yet another embodiment of the present disclosure;

FIG. 8 is a schematic diagram of an exemplary process according to anembodiment of the present disclosure;

FIG. 9 is a schematic diagram of another exemplary process according toan embodiment of the present disclosure;

FIG. 10 is a schematic diagram of yet another exemplary processaccording to an embodiment of the present disclosure;

FIG. 11 is a schematic diagram of still another exemplary processaccording to an embodiment of the present disclosure;

FIG. 12 is a schematic diagram of yet another exemplary processaccording to an embodiment of the present disclosure;

FIG. 13 is a schematic diagram of still another exemplary processaccording to an embodiment of the present disclosure;

FIG. 14 is a schematic diagram of yet another exemplary processaccording to an embodiment of the present disclosure;

FIG. 15 is a schematic diagram of an exemplary process of adjustingconfigurations of a master device and a slave device;

FIG. 16 is a schematic diagram of another exemplary process of adjustingthe configurations of the master device and the slave device;

FIG. 17 is a flowchart showing a process example of a communicationmethod according to an embodiment of the present disclosure;

FIG. 18 is a block diagram showing a configuration example of acommunication device for user side according to an embodiment of thepresent disclosure;

FIG. 19 is a flowchart showing a process example of a communicationmethod according to an embodiment of the present disclosure;

FIG. 20 is a block diagram showing an exemplary structure of a computerfor implementing the method and the device of the present disclosure;

FIG. 21 is a block diagram showing a schematic configuration of a smartphone to which a content of the present disclosure may be applied; and

FIG. 22 is a block diagram showing an example of a schematicconfiguration of a vehicle navigation device to which the content of thepresent disclosure may be applied.

DETAILED DESCRIPTION OF EMBODIMENTS

Hereinafter embodiments of the present disclosure are described withreference to the drawings. Elements and features described in onedrawing or one embodiment of the present disclosure may be combined withelements and features described in one or more other drawings orembodiments. It should be noted that, indication and description ofcomponents and processing which are not related to the presentdisclosure or well known for those skilled in the art are omitted in thedrawings and illustrations for clarity.

As shown in FIG. 1, a communication device 100 according to anembodiment of the present disclosure includes an acquiring unit 110, adetermining unit 120 and a triggering unit 130.

The acquiring unit 110 is configured to acquire information on adistribution of user equipments in a dynamic network. The distributioninformation acquired by the acquiring unit 110 includes at leastinformation on a distribution of a slave device. The slave device is,for example, a user equipment which obtains a communication service viaa master device during a device-to-device (D2D) communication. In someexamples, the slave device is machine-to-machine (M2M) device whichtransmits data via the master device during an M2M communication. Inaddition, according to specific applications, the distributioninformation acquired by the acquiring unit 110 may also include thedistribution information of a master device. Accordingly, the masterdevice is, for example, a user equipment which forwards data to anotherD2D/M2M device during a D2D/M2M communication. For example, the masterdevice may communicate with a network infrastructure such as a basestation.

FIG. 2 shows an example of a communication system to which an embodimentof the present disclosure may be applied. As an example, FIG. 2 shows acommunication system in a D2D communication scene based on 3GPP, andsubsequent embodiments are described mainly for such application scene.However, scenes to which the embodiments of the present disclosure maybe applied are not limited to the example. The embodiments of thepresent disclosure may also be applied to other dynamic networks, suchas a P2P network, an Ad hoc network and a heterogeneous network based onWiFi, etc.

The exemplary system shown in FIG. 2 includes a base station (such as aneNB) and multiple communication devices, where the communication devicesinclude a master device such as a master D2D device A, a master D2Ddevice B and a master D2D device C, and a slave D2D device. A slave D2Ddevice located in a signal coverage of a respective master D2D devicemay perform data communication with the respective master D2D device,and may obtain other communication services via the respective masterD2D device, for example communicating with the eNB and acquiringservices such as radio resource management via the respective master D2Ddevice.

The communication device 100 according to the embodiment of the presentdisclosure may be implemented as a communication device on userequipment side such as a master D2D device or may be implemented as acommunication device on base station side. In addition, functions of thecommunication device 100 may be achieved in cooperation by devicesdistributed on the user side and the base station side.

Referring to FIG. 1 again, the determining unit 120 is configured todetermine a reconfiguration scheme of the dynamic network according tothe information acquired by the acquiring unit 110.

For example, the reconfiguration scheme may include a reselection of themaster device and/or a resetting of an operation parameter of the masterdevice. More specifically, the resetting of the operation parameter ofthe master device includes adjusting a transmission power of the masterdevice and/or adjusting a slave device served by the master device (forexample, adjusting a device ID in a slave device list). It should benoted that, the reselection of a master device generally corresponds toa case where the communication device 100 is implemented as a device onbase station side, but the present disclosure is not limited thereto.For example, in an application scene where a user equipment (UE) mayserve as a central management node, the communication device 100 on theUE side (for example a cluster head of a D2D device cluster) may beconfigured to perform the reselection of a master device.

The triggering unit 130 is configured to trigger a reconfiguration to beperformed on the dynamic network according to the scheme determined bythe determining unit 120. For example, the triggering unit 130 maynotify a corresponding device to perform the reconfiguration by acontrol signaling. In an example in which the communication device 100is implemented as a device on base station side, the triggering unit 130may notify the corresponding master device to reconfigure a D2Dtransmission power, for example, by power control information carried bya physical downlink control channel (PDCCH), and notify thecorresponding master device to adjust a slave user served by the masterdevice by, for example, a control element of a MAC layer carried on aphysical downlink shared channel (PDSCH). In an example in which thecommunication device 100 is implemented as a device on user side such asa master device, the triggering unit 130 transmits a message of stoppingthe D2D communication to a slave device to be released by high-layersignaling carried on a physical uplink shared channel (PUSCH), so as totrigger a reconfiguration.

As described above, the processing performed by the communication device100 according to the embodiment of the present disclosure may beperformed on the user equipment side, the base station side or may beperformed by the user equipment side in cooperation with the basestation side. Next, exemplary manners for triggering distributionmeasurement of a user equipment in a dynamic network according to anembodiment of the present disclosure and determining a configuration ofthe dynamic network are described with reference to FIG. 3 to FIG. 5respectively.

FIG. 3 shows an example in which node distribution measurementtriggering and system reconfiguration determination are both performedon base station side.

In process (1), an eNB triggers a node measurement. Feasible triggeringconditions may include: the eNB needs to perform resource allocation andscheduling on a D2D device based on a node distribution measurementresult. For example, the eNB determines to adjust a power level of theD2D device or adjust an available resource pool such as a resource poolfor D2D discovery and a resource pool for D2D communication, based on achange in network state.

In process (2), node distribution measurement is performed between therelated devices such as the eNB, a master D2D device or a D2D device.

In process (3), the eNB determines a system/resource reconfigurationaccording to a result of the node distribution measurement.

FIG. 4 shows an example in which a master D2D device performs nodedistribution measurement triggering and system reconfigurationdetermination.

In process (1), the master D2D device triggers a node distributionmeasurement. Feasible triggering conditions may include: a change of theavailable resource of the master D2D device, for example the eNBnotifies the master D2D device to change a power or an selectableresource pool; a change of the state of the master D2D device itself,for example a periodical timing apparatus provided in the master D2Ddevice for triggering distribution measurement is started, the mobilityof the master D2D device changes (for example, the position begins tochange and a measurement reporting event which may result in a switchingoccurs), or the battery level is lower than a threshold; and a change ofstate of a slave D2D device served by the master D2D device, for examplea reduction of throughout or a reduction of link quality.

In process (2), node distribution measurement is performed between therelated devices such as the eNB, the master D2D device or a D2D device.

In process (3), the master D2D device determines a system/resourcereconfiguration based on a result of the node distribution measurement.

FIG. 5 shows an example in which a master D2D device triggers a nodedistribution measurement and an eNB determines a system reconfiguration.

In process (1), the master D2D device triggers node distributionmeasurement. Feasible triggering conditions are similar to thosedescribed above with reference to FIG. 4.

In process (2), node distribution measurement is performed between therelated devices such as the eNB, the master D2D device or a D2D device.

In process (3), the eNB determines a system/resource reconfigurationaccording to a result of the node distribution measurement.

Next, specific embodiments in which the communication device is a masteruser equipment and a network infrastructure are described respectively.

According to an embodiment, the communication device is a master userequipment. In other words, another communication device may obtain acommunication service via the communication device according to theembodiment, for example, for performing data communication with a basestation or obtaining a radio resource management service from the basestation and so on.

FIG. 6 shows a configuration example of a communication device 600according to an embodiment of the present disclosure. The communicationdevice 600 includes an acquiring unit 610, a determining unit 620, atriggering unit 630 and a distribution measurement triggering unit 640.Configurations of the acquiring unit 610, the determining unit 620 andthe triggering unit 630 are similar to the configurations of theacquiring unit 110, the determining unit 120 and the triggering unit 130described above with reference to FIG. 1. The information ondistribution of user equipments acquired by the acquiring unit 610 mayinclude information on distribution of user equipments in a range servedby the communication device 600, i.e., a signal coverage. Thedistribution information includes a density of the user equipments, forexample.

The distribution measurement triggering unit 640 is configured totrigger, based on a predetermined event, the user equipment in thesignal coverage of the communication device 600 to transmit adistribution measurement signal, for the acquiring unit 610 to determinethe information on the distribution of the user equipments.

For example, the distribution measurement triggering unit 640 maytrigger a distribution measurement based on one or more of the followingevents:

(1) a change in a mobility characteristic of the communication device600 satisfies a predetermined condition, for example, a change ofposition, speed or moving direction, or occurrence of cell handover, acarrier aggregation change (for example increasing or decreasing ofsecondary cells), or a dual connection change (for example establishingor releasing of a dual connection with a base station), etc.;

(2) a change in signal transmission parameter of the communicationdevice 600 exceeds a predetermined threshold, where the signaltransmission parameter may include, for example, a power configured bythe base station, a modulation and coding scheme (MCS), an availableresource pool between the served slave user equipment, etc, and may alsoinclude a change in transmission power caused by a change in batterylevel of the communication device 600 itself;

(3) a timer for triggering distribution measurement satisfies a timingcondition, where the condition corresponds to an overall configurationof distribution measurement performed periodically; and

(4) a communication state between the communication device 600 and aslave user equipment served by the communication device 600 satisfies apredetermined condition, for example, a channel quality is lower than apredetermined level.

In addition, the distribution measurement triggering unit 640 maytrigger a user equipment in the signal coverage of the communicationdevice 600 to transmit a distribution measurement signal by at least oneof:

(1) transmitting a broadcast signal related to a distributionmeasurement request (a first broadcast signal) to user equipments in thesignal coverage of the communication device 600, for example, areference signal for D2D communication (including a D2D discoverysignal, a D2D synchronization signal or a newly defined signal and soon); and

(2) transmitting a distribution measurement request message to a servingbase station of the communication device 600, so as to trigger, via theserving base station, the user equipment in the signal coverage of thecommunication device 600 to transmit a distribution measurement signal.

Exemplary processes in which a master D2D device triggers distributionmeasurement and determines a reconfiguration based on a result of thedistribution measurement will be described in more detail with referenceto FIG. 8 to FIG. 10 later.

As described above, the acquiring unit 610 may be configured to acquirea density of user equipments in a signal coverage of the communicationdevice 600 serving as a master D2D device. In addition, the acquiringunit 610 may estimate a density of user equipments in the signalcoverage of the communication device 600 by using a broadcast signal (asecond broadcast signal) transmitted by a user equipment which does notserve as a slave device served by the communication device 600 as adistribution measurement signal. The broadcast signal may include a D2Ddiscovery signal, a D2D synchronization signal or a newly defined signaland so on.

For example, a user equipment in the signal coverage of thecommunication device 600 which is not served by the communication device600 may transmit a broadcast signal containing a user identity (a secondbroadcast signal) (such as a D2D discovery signal) with a certain signalstrength, in response to a broadcast signal (a first broadcast signal)related to a distribution measurement request from the communicationdevice 600, or spontaneously. The communication device 600 may interceptsecond broadcast signals from user equipments around, for example, countthe user equipments of which a strength of the second broadcast signalexceeds a predetermined signal strength threshold. An identifier of auser equipment may be obtained by signal analysis, and the same userequipment is counted only once. A sum of the number of users which arenot served by the communication device 600 within a period of time andthe number of slave user equipments which are served may be counted, andthe sum is divided by an effective signal coverage area to obtain adensity of the user equipments in the current effective signal coverage.It should be understood by those skilled in the art that the way forobtaining the density of the user equipments is not limited to theexemplary manner.

For example, a user equipment may report its position to a certaingeographical position management module, and the communication device600 serving as the master user equipment may report its powerconfiguration information to the geographical position managementmodule. Therefore, the geographical position management module maycalculate the number of the user equipments in the effective signalcoverage of the communication device 600 and divide the number of theuser equipments by the effective signal coverage area to obtain adensity of users in the current effective signal coverage.

Accordingly, as shown in FIG. 7, a communication device 700 according toan embodiment of the present disclosure includes an acquiring unit 710,a determining unit 720, a triggering unit 730 and a reporting unit 740.Configurations of the determining unit 720 and the triggering unit 730are similar to the determining unit 120 or 620 and the triggering unit130 or 630 described above with reference to FIG. 1 and FIG. 6,respectively. The reporting unit 740 is configured to report informationon a position and/or a transmission power of the communication device700 to a network infrastructure such as an eNB. The acquiring unit 710is configured to acquire information on a density of user equipments ina signal coverage of the communication device 700 from the networkinfrastructure.

In whatever way the information on the density of the user equipments inthe signal coverage is obtained, the determining unit of thecommunication device according to the embodiment of the presentdisclosure can determine an operation parameter of the communicationdevice according to a predetermined relation between the density of theuser equipments and a network performance. Specifically, the operationparameter may include a transmission power of the communication deviceand/or the maximum number of slave devices served by the communicationdevice. The maximum number of the slave devices served by thecommunication device is a parameter for limiting the number of slave D2Ddevices associated with one master D2D device, that is, the number ofthe slave D2D devices served by the master D2D device should be lessthan or equal to the maximum number.

For example, configurations of the master/slave D2D device in which anetwork performance is optimized for different node densities may beestimated by pre-calculation. The network performance may include asystem capacity and a system throughput and so on. The configurations ofthe master/slave D2D device may include: a distribution density ofmaster D2D devices, or a minimum distance between master D2D devices; amaximum power of a master D2D device or an effective signal coverageradius of a master D2D device; the maximum number of slave D2Ds whichmay be associated with one master D2D and so on.

In addition, node densities may be divided into different intervals andresults of node distribution measurements are determined based on theintervals. For example, if a node density measured currently and thenode density measured previously belong to different intervals, theoperation parameter is adjusted, for example, initiating a reselectionof the master/slave D2D and an adjustment of the power of the master D2Ddevice. In another aspect, if the node density measured currently andthe node density measured previously belong to the same interval, it isfurther determined whether a difference between the two measurementresults exceeds a specific threshold. If the difference exceeds thethreshold, the operation parameter is adjusted; otherwise, the currentoperation parameter is not changed. As an example, the specificthreshold may be set as a half of a length of the interval. For example,if an interval of the number of nodes is [a, b], the threshold may beset as |a−b|/2.

Next, an exemplary manner in which the optimal configuration of themaster/slave D2D is estimated according to the node density isdescribed.

Firstly, a reference mutually exclusive distance is calculated. Given atransmission power and a reference user parameter of a base station, amutually exclusive distance of master D2D devices under a D2D networkstructure is calculated as a reference mutually exclusive distance,according to a certain optimization object. The reference user parameterincludes: a user density λ₀ (an average user density counted by anetwork may be selected), an allowable maximum transmission powerP_(0,max) for communication between users, an SINR threshold T requiredfor normal communication between users, and a path loss index α.Specifically, an effective transmission distance between user equipmentsmay be determined according to the transmission power. The userequipments can not communicate if a distance between the user equipmentsis greater than the effective transmission distance. That is,distribution of master user equipments should at least satisfy thatslave user equipments served by a master user equipment may transmit andreceive a signal with the master user equipment. In addition, accordingto the transmission power and the SINR requirement of user equipments,the distribution of master user equipments should further satisfy that asignal received on a link formed between a master user equipment and aserved slave user equipment thereof using the same spectrum resource andan interference on the link should satisfy the SINR requirement. Forexample, based on the above optimization object, the reference mutuallyexclusive distance D₀ may be determined by many manners.

Subsequently, a coverage radius r₀ of a master D2D device and a usercoverage radius r₁ corresponding to an actual user density λ₁ arecalculated according to a capacity of the master D2D device. Thecapacity of the master D2D device indicates the number N_(s) of slaveD2D devices which can be supported by the master D2D device. Accordingto the setting, a user distribution conforms to a PPP model. The numberof nodes in a specific graph A is λ₀|A|, where |A| indicates an area ofthe graph A. Therefore it can be obtained λ₀πr₀ ²=N_(s)+1. Further, itcan be obtained

$r_{0} = {\sqrt{\frac{N_{s} + 1}{\lambda_{0}\pi}}.}$Similarly, it can be obtained

$r_{1} = {\sqrt{\frac{N_{s} + 1}{\lambda_{1}\pi}}.}$

Subsequently, an actual mutually exclusive distance D₁ and an actualmaximum power P_(1,max) corresponding to the actual node density areobtained according to the reference mutually exclusive distance. Theactual maximum power ensures that a reception power of a user at an edgeof a coverage is consistent with that in the reference case and does notexceed the allowable maximum transmission power P_(0, max) forcommunication between users, thus it can be obtained

$P_{1,\max} = {\min{\left\{ {P_{0,\max},{P_{0,\max}\left( {\lambda_{0}\text{/}\lambda_{1}} \right)}^{\frac{\alpha}{2}}} \right\}.}}$Under the assumption, the mutually exclusive distance is directlyproportional to the effective coverage radius of the master D2D device,thus it can be obtained that the actual mutually exclusive distance is

$D_{1} = {{D_{0}\left( {\lambda_{0}/\lambda_{1}} \right)}^{\frac{1}{2}}.}$

It should be understood that the way for determining the operationparameter of the communication device by the determining unit of thecommunication device according to the embodiment of the presentdisclosure based on the density of user equipments is not limited tospecific details described in the above embodiment.

According to a relation between a target value of the determinedoperation parameter and current an actual value of the operationparameter, the determining unit may further determine an adjustmentmanner of the operation parameter according to different principles. Forexample, in a case that an actual transmission power of thecommunication device is greater than the determined target transmissionpower, the determining unit may determine the adjustment manner of theoperation parameter based on the following principles:

(1) reducing the transmission power while ensuring a signal quality ofthe slave device; or

(2) removing the served slave devices sequentially in an ascending orderof communication qualities of the slave devices and reducing thetransmission power, until the transmission power does not exceed thedetermined transmission power.

In the above manner (1), a transmission power of the master device isreduced as much as possible without changing the number of the servedslave devices, such that the transmission power of the master device iscloser to the target transmission power, to improve the systemperformance.

In the above manner (2), the served slave devices are removed accordingto priorities of the communication qualities, such that the transmissionpower of the master device is close to the target transmission power asmuch as possible, to improve the system performance.

However, the present disclosure is not limited to the two mannersdescribed above. For example, the two manners may be combined, and theadjustment manner of the parameter can be determined with a tradeoffbetween the maintaining of the number of the slave devices and thereducing of the transmission power of the master device.

In addition, there is also a possible case where the actual transmissionpower of the communication device is less than the determined targettransmission power, and it is expected to increase the number of thesalve devices served by the communication device. In this case, theadjustment manner of the operation parameter may be determinedsimilarly, for example, increasing the transmission power of thecommunication device and increasing the number of the slave devices andso on.

After the determining unit determines the adjustment manner of theoperation parameter of the communication device, the triggering unit maytrigger a corresponding process for adjusting the parameter. Forexample, it may be triggered to adjust a transmission power of thecommunication device according to the determined transmission power. Inaddition, a D2D communication releasing request may be transmitted tothe slave device of the communication device, and a D2D communicationestablishing request may be transmitted to a user equipment, in thesignal coverage of the communication device, which does not serve as theslave device of the communication device, and so on.

Next, exemplary processes in which a D2D device initiates distributionmeasurement and determines a reconfiguration based on a result of thedistribution measurement when the communication device according to anembodiment of the present disclosure is a master D2D device, aredescribed with reference to FIG. 8 to FIG. 10.

In an exemplary process shown in FIG. 8, at process (1), a master D2Ddevice, i.e., the communication device according to the embodiment,triggers node distribution measurement. As described above, the triggercondition may include, for example, a change in an available resource ofthe master D2D device, a change in a state of the master D2D deviceitself, and a change in a state of the served slave D2D device, and soon.

At (2.1), the D2D device (which does not serve as a slave device yet)autonomously transmits a node distribution measurement signal. The nodedistribution measurement signal may carry an ID of the D2D device and/ora transmission power of the signal. The signal may be a signal definedby the D2D system such as a D2D discovery signal or a D2Dsynchronization signal, or may be a new reference signal which isdefined specially. The node distribution measurement signal may betransmitted periodically by the D2D device, or may be triggered by theD2D device in some conditions. The conditions include, for example,reduction of a link quality, adjusting of a power and moving of a node.In this case, the master D2D device may directly enter an interceptionphase for the signal after triggering the node distribution measurement.

At (2.2), the D2D device analyzes the intercepted node distributionmeasurement signal to confirm a change in the number of nodes around.Different analysis methods are used according to different informationcarried in the node distribution measurement signal in the system. Forexample, if the signal is a heartbeat signal transmitted with a fixedpower, the master D2D device may estimate a distance from a transmissionpoint according to t strength of the received signal. For example, astrength of a signal received by the master D2D device transmitted by aD2D node at an edge of the effective signal coverage of the master D2Ddevice may be used as a threshold. A D2D device is determined to belocated in the effective coverage of the master D2D device if a strengthof the received corresponding signal is higher than the threshold; and aD2D device is determined to be located out of the effective coverage ofthe master D2D device if a strength of the received corresponding signalis lower than the threshold. The master D2D device may count only thenodes in its effective coverage. The node distribution measurementsignal may carry an ID of a transmission node, or signals for respectivetransmission nodes may be distinguished in other ways, to avoidrepetitive counting. If there is no node distinguishing information andeach D2D device transmits a signal periodically with a fixed frequency,the number of repetitive counting may be estimated based on a detectiontime range.

Next, in process (3), the master D2D device determines the adjustment ofthe operation parameter according to an interception result of thedistribution measurement signal.

During the exemplary process shown in FIG. 8, the D2D deviceautonomously transmits a node distribution measurement signal. However,the D2D device may transmit the node distribution measurement signal inresponse to triggering from the master D2D device.

As shown in FIG. 9, at process (1), the master D2D device triggers nodedistribution measurement.

At (2.2), the master D2D device transmits a node distributionmeasurement triggering signal, which may carry an ID of the master D2Ddevice and/or a transmission power of the signal. The signal may be asignal defined by the D2D system, for example, a D2D discovery signal ora D2D synchronization signal, or may be a new reference signal which isdefined specially.

At (2.3), the master D2D device enters an interception phase for thenode distribution measurement signal.

At (2.4), the D2D device may intercept and analyze the node distributionmeasurement triggering signal from the master D2D device. The D2D devicemay periodically trigger the interception and analysis, or may triggerthe interception and analysis in a case of a poor channel condition, tosearch for a better serving node. The D2D device selects whether totransmit a node distribution measurement signal according to an analysisresult. For example, if an analyzed ID of the master D2D device belongsto an allowable and willing feedback range (“the willing feedback range”means that feedback is performed to only a master D2D of which an IDbelongs to a certain range, for example), it is triggered to transmit anext node distribution measurement signal. In addition, the D2D devicemay estimate, based on a transmission power of a signal and a strengthof the received signal, an attenuation condition of the signal, so as todetermine a link quality; and feedback is performed only in a case thatthe link quality exceeds a certain threshold (the threshold may be athreshold which can ensure normal communication or a quality of a linkproviding a service currently); otherwise, the D2D may ignore the nodedistribution measurement triggering signal.

At (2.5), the D2D device transmits a node distribution measurementsignal which may carry an ID of the D2D device and/or a transmissionpower of the signal. The signal may include a D2D discovery signal, aD2D synchronization signal or a new reference signal defined specially.

At (2.6), the master D2D device analyzes the intercepted nodedistribution measurement signal, to confirm a change in the number ofnodes around. Different analysis methods are used according to differentinformation carried in the node distribution measurement signal in thesystem. Specific ways are similar to the process (2.2) illustrated withreference to FIG. 8 above, which are not repeated here.

Next, At process (3), the master D2D device determines the adjustment ofthe operation parameter according to an interception result of thedistribution measurement signal.

During an exemplary process shown in FIG. 9, a D2D device transmits anode distribution measurement signal in response to triggering of amaster D2D device. In addition, the master D2D device may transmit anode distribution measurement request to a base station, and the basestation requests the D2D device to transmit a node distributionmeasurement signal.

As shown in FIG. 10, during process (1), a master D2D device triggersnode distribution measurement.

At (2.1), the master D2D device transmits a node distributionmeasurement request to an eNB, and the request may include ageographical position of the master D2D device, a radius of an effectivesignal coverage and the number of nodes in a current effective signalcoverage and so on. The request may be transmitted by a physical uplinkcontrol channel (PUCCH), a certain defined media access control element(MAC CE) or high layer signaling such as RRC signaling.

At (2.2), the master D2D device enters an interception phase for thenode distribution measurement signal.

At (2.3), the eNB transmits a node distribution measurement signaltransmitting request to a D2D device satisfying a condition. The requestmay include an ID of the master D2D device, a time range for measurementand/or time points corresponding to each of the D2D devices which arerandomly generated during the time range. The request may be transmittedby broadcasting or a communication link for each selected D2D device.The request may be transmitted by PDCCH, a certain defined MAC CE orhigh layer signaling such as RRC signaling.

At (2.4), the D2D device analyzes the received node distributionmeasurement signal transmitting request, and selects whether to transmita node distribution measurement signal according to an analysis result.If an analyzed ID of the master D2D device belongs to the allowable andwilling feedback range, it is triggered to transmit a next nodedistribution measurement signal. Further, if the node distributionmeasurement signal transmitting request transmitted by the eNB includesinformation of the master D2D device such as a position and a coverage,the D2D device may estimate, based on a transmission power of a signaland a strength of the received signal, an attenuation condition of thesignal, to determine a link quality. Feedback is performed only in acase that the link quality exceeds a certain threshold.

Subsequent processes (2.5) to (3) are similar to the processes (2.5) to(3) described with reference to FIG. 9, which are not repeated here.

The exemplary embodiments in a case that the communication device is themaster D2D device are described above. Next, an exemplary embodiment inwhich the communication device is a network side infrastructure such asa base station is described.

Referring to FIG. 1 again, in a case that the communication device 100according to the embodiment of the present disclosure is a networkinfrastructure such as a base station, the information on thedistribution of the user equipments in the dynamic network acquired bythe acquiring unit 110 of the communication device 100 may include adensity of the user equipments in a specific region. The specific regionincludes for example a service coverage of the base station or a part ofthe coverage. More specifically, the acquiring unit 110 may estimate thedensity according to information from master devices in the specificregion and/or information from the user equipments in the specificregion which do not serve as a slave device.

Accordingly, the determining unit 120 of the communication device 100according to the embodiment is configured to determine an operationparameter of a user equipment in the region according to a predeterminedrelation between the density of the user equipments and a networkperformance.

Specifically, the operation parameter determined by the determining unit120 may include a target density of master devices, a spacing thresholdof master devices, a transmission power threshold of a master device anda threshold of the number of slave devices served by a master device andso on.

As described above, the operation parameter that optimize the networkperformance for different node densities may be estimated bypre-calculation, and specific ways are similar to the exemplary waysdescribed in detail above, which are not repeated here.

The triggering unit 130 may be configured to transmit a master devicecanceling request to a master device in the specific region, transmit amaster device setting request to a user equipment in the region ortransmit a power alteration instruction and/or a slave user alterationinstruction to a master device in the region. In other words, in theembodiment, the communication device 100 serving as the base station maydetermine the specific selection of master D2D devices, and determinethe operation parameter of a master D2D such as a transmission power andthe maximum number of slave D2D devices. For example, the base stationmay select master D2D terminals sequentially according to a descendingorder of strength of signal from D2D device to the base station, andensures that a mutually exclusive distance is satisfied therebetween.

Next, exemplary processes that a base station initiates distributionmeasurement and determines a reconfiguration based on a result of thedistribution measurement when the communication device according to anembodiment of the present disclosure is the base station are describedwith reference to FIG. 11 to FIG. 13 and an exemplary process that amaster D2D device initiates distribution measurement and a base stationdetermines a reconfiguration based on a result of the distributionmeasurement is described with reference to FIG. 14, without repeatingspecific details described above with reference to FIG. 8 to FIG. 10.

During an exemplary process shown in FIG. 11, at process (1), the basestation triggers node distribution measurement. As described above, thetriggering conditions may include, for example, an eNB needs to performresource allocation and scheduling on the D2D device according to thenode distribution measurement result, for example, adjusting a powerlevel or an available resource pool of the D2D device and so on.

At (2.1), the eNB transmits a node distribution measurement request tothe selected master D2D device. The request may be transmitted by PDCCH,a certain defined MAC CE or a high layer signaling such as RRCsignaling.

Subsequent processes (2.2) to (2.6) are similar to the processes (2.2)to (2.6) described above with reference to FIG. 9, which are notrepeated here.

At (2.7), the master D2D device reports the node distributionmeasurement result to the eNB.

At (3), the base station determines an adjustment of an operationparameter based on the node distribution measurement result.

In an exemplary process shown in FIG. 12, in process (1), the basestation triggers node distribution measurement.

At (2.1), the eNB transmits a node distribution measurement request tothe selected master D2D device.

Subsequent processes (2.2) to (2.6) are similar to the processes (2.2)to (2.6) described above with reference to FIG. 10, which are notrepeated here.

At (2.7), the master D2D device reports the node distributionmeasurement result to the eNB.

At (3), the base station determines the adjustment of the operationparameter based on the node distribution measurement result.

In an exemplary process shown in FIG. 13, at process (1), a base stationtriggers node distribution measurement.

At (2.1), the eNB transmits a node distribution measurement signaltransmitting request to a D2D device satisfying a condition. The requestmay be transmitted via PDCCH, a certain defined MAC CE or a high layersignaling such as RRC signaling.

At (2.2), the D2D device analyzes the received node distributionmeasurement signal transmitting request, and decides whether to transmita node distribution measurement signal according to an analysis result.

At (2.3), the D2D device feeds back node distribution measurementinformation to the eNB. The information may carry position informationof the transmission node (for example a longitude and a latitude of thenode). Therefore, the base station may determine distribution of the D2Ddevice based on the position information.

At (3), the base station determines an adjustment of the operationparameter based on the node distribution measurement result.

The example shown in FIG. 14 differs from the example shown in FIG. 13in that: at process (1), the master D2D device triggers nodedistribution measurement; and at process (2.0), the master D2D devicetransmits a node distribution measurement request to the eNB. Subsequentprocesses (2.1) to (3) are similar to corresponding processes describedwith reference to FIG. 13, which are not repeated here.

Next, exemplary processes of a dynamic network reconfiguration triggeredby the communication device according to an embodiment of the presentdisclosure are described with reference to FIG. 15 and FIG. 16.

FIG. 15 shows an example of a process that a master D2D device reselectsa salve D2D device and adjusts a power of the master D2D device.

At process (1), the master D2D device initiates reselection of the slaveD2D device.

At process (2), the master D2D device transmits an association releasingrequest to a selected associated slave D2D device.

At process (3), the associated slave D2D device feeds back anassociation releasing response.

At process (4), the master D2D device transmits an associationestablishing request to a selected and newly associated slave D2Ddevice.

At process (5), the newly associated slave D2D device feeds back anassociation establishing response.

At process (6), the master D2D device determines whether to adjust apower.

At process (7), the master D2D device and the selected associated slaveD2D device perform an association releasing process.

At process (8), the master D2D device and the selected unassociatedslave D2D device perform an association establishing process.

At process (9), the master D2D device reports an association result to abase station.

Specifically, in process (1), the master D2D device may reselect theserved slave D2D devices in a descending order of strengths of thereceived D2D device signals, such that the number of the slave D2Ddevices does not exceed the maximum number of slave D2D devices whichcan be carried. In process (6), the master D2D device adjusts a poweraccording to a link condition of a D2D device in the selected nodeshaving a lowest signal strength, such that a quality of a signalreceived by the D2D device reaches a normal communication level. If thepower exceeds a maximum transmission power allowed by the system for amaster D2D to serve a slave D2D, the slave D2D device with the lowestsignal strength may be removed, a slave D2D device with a second lowestsignal strength is considered, until the transmission power of themaster D2D does not exceed the maximum transmission power. In process(9), the selection result reported to the base station by the master D2Ddevice may include: the number of the served slave D2D devices and/or atransmission power level for serving slave D2D devices and so on.

FIG. 16 shows an exemplary process that a base station determinesreselection of a master/slave D2D and power adjustment of the master D2Ddevice.

At process (1), the base station reselects a master D2D device accordingto a node distribution measurement result.

At process (2), the base station transmits a master D2D cancelingrequest to an original D2D device.

At process (3), the original D2D device and a served slave D2D devicethereof perform an association releasing process.

At process (4), the original D2D device feeds back a master D2Dcanceling response to the eNB.

At process (5), the base station transmits a master D2D setting requestto a selected new master D2D device. The request may include a maximumavailable power of the master D2D device and the maximum number ofserved slave D2D devices and so on.

At process (6), the new master D2D device performs a process ofselection and association for slave D2D devices.

At process (7), the new master D2D device feeds back a master D2Dsetting response to the eNB.

Specifically, at process (1), the base station may select master D2Dterminals sequentially in a descending order of strength of signal fromD2D terminal to the base station, and ensuring a mutually exclusivedistance therebetween is satisfied. That is, there is no other masterD2D device in a circle centered at the selected master D2D device andhaving a radius of the mutually exclusive distance. At process (5), thebase station notifies the selected D2D of a selection result whichincludes the D2D device serving as the master D2D device, a maximumtransmission power of the D2D device and the maximum number of slave D2Ddevices which can be associated with the D2D device.

In addition, the D2D device may autonomously perform master/slave D2Dreselection and power adjustment of the D2D device.

Alternatively, the base station may transmit a master/slave D2Dreselection request to all D2D devices. The request includes aconfiguration of master/slave D2D devices in an interval to which thenode distribution measurement result belongs. The D2D device may becomea master D2D device by competing and negotiating, so as to satisfy adistribution condition of master D2D devices. Then, the master D2Ddevice selects a served slave D2D device and establishes a connectionwith the slave D2D device by reselecting the slave D2D device andadjusting a power of the master D2D device.

Next, a communication method performed by the communication deviceaccording to the embodiment of the present disclosure is describedwithout repeating the specific details described above.

As shown in FIG. 17, the communication method according to an embodimentof the present disclosure includes the following steps.

In step S1710, information on distribution of user equipments in adynamic network is acquired, where the user equipments include at leasta slave device which obtains a communication service via a master deviceduring a device-to-device communication.

In step S1720, a reconfiguration scheme of the dynamic network isdetermined according to the acquired information.

In step S1730, a reconfiguration to be performed on the dynamic networkaccording to the determined scheme is triggered.

The method according to the embodiment of the present disclosure may beperformed by a network infrastructure such as a base station, may beperformed by a user equipment serving as a master D2D device or may beperformed by the network infrastructure in cooperation with thecommunication device. In other words, the above steps S1710, S1720 andS1730 each may be performed by the network infrastructure, or the userequipment, or the network infrastructure in cooperation with the userequipment.

In addition, embodiments of the present disclosure also include a userequipment serving as a non-master D2D device, the user equipment mayserve as “(a) D2D device” described in FIG. 8 to FIG. 14 in the dynamicnetwork.

As shown in FIG. 18, a communication device 1800 according to theembodiment includes a receiving unit 1810 and a transmitting unit 1820.

The receiving unit 1810 is configured to receive a transmitting requestfrom a user equipment (for example, a master D2D device) or a networkinfrastructure (for example, a base station). For example, the receivingunit 1810 may receive the transmitting request by PDCCH or MAC CE.

The transmitting unit 1820 is configured to transmit, when thecommunication device 1800 does not serve as a slave device, a referencesignal for determining distribution of the communication device 1800 inthe dynamic network based on the received transmitting request. Thereference signal may include identifier information of the communicationdevice 1800.

In a case that a time configuration for transmitting the referencesignal is indicated in the transmitting request, the transmitting unit1820 may transmit the reference signal according to the indicated timeconfiguration.

In addition, the receiving unit 1810 may receive a broadcast signalincluding a transmitting request from the user equipment, and thetransmitting unit 1820 may transmit the reference signal only in a casethat a strength of the received broadcast signal including thetransmitting request is higher than a predetermined level.

According to an embodiment of the present disclosure, a communicationmethod performed by a user equipment is further provided, and the userequipment may serve as “(a) D2D device” described in FIG. 8 to FIG. 14in a dynamic network.

As shown in FIG. 19, the communication method performed by thecommunication device according to the embodiment includes the followingsteps.

In step S1910, a transmitting request from a user equipment or a networkinfrastructure is received.

In step S1920, in a case that the communication device does not serve asa slave device, a reference signal for determining distribution of thecommunication device in a dynamic network is transmitted based on therequest.

In addition to the above embodiments, according to an embodiment of thepresent disclosure, a communication device is further provided. Thecommunication device includes a circuit or one or more processorsconfigured to: acquire information on distribution of user equipments ina dynamic network, where the user equipments include at least a slavedevice which obtains a communication service via a master device duringa device-to-device communication; determine a reconfiguration scheme ofa dynamic network according to the acquired information; and trigger areconfiguration to be performed on the dynamic network according to thedetermined scheme.

In addition, according to another embodiment of the present disclosure,a communication device is provided, which includes a circuit or one ormore processors configured to: receive a transmitting request from auser equipment or a network infrastructure; and transmit, when thecommunication device does not serve as a slave device, a referencesignal for determining distribution of the communication device in adynamic network.

As an example, various steps of the methods above and various modulesand/or units of the devices above may be implemented as software,firmware, hardware or a combination thereof. In a case of implementingby software or firmware, programs consisting of the software forimplementing the methods above are installed to a computer with adedicated hardware structure (for example a general-purpose computer2000 shown in FIG. 20) from the storage medium or the network. Thecomputer can perform various types of functions when installed withvarious types of programs.

In FIG. 20, a central processing unit (CPU) 2001 performs various typesof processing according to programs stored in a read only memory (ROM)2002 or programs loaded from a storage section 2008 to a random accessmemory (RAM) 2003. Data required when the CPU 2001 performs varioustypes of processing is also stored in the RAM 2003 as needed. The CPU2001, the ROM 2002 and the RAM 2003 are linked to each other via a bus2004. An input/output interface 2005 is also linked to the bus 2004.

The following components are linked to the input/output interface 2005:an input section 2006 (including a keyboard, and a mouse and so on), anoutput section 2007 (including a display, for example a cathode ray tube(CRT) and a liquid crystal display (LCD), and a loudspeaker), a storagesection 2008 (including a hard disk and so on), and a communicationsection 2009 (including a network interface card for example a LAN card,and a modem). The communication section 2009 performs communicationprocessing via a network for example the Internet. A driver 2010 mayalso be linked to the input/output interface 2005 as needed. A removablemedium 2011 for example a magnetic disk, an optical disk, amagnetic-optical disk and a semiconductor memory may be installed on thedriver 2010 as needed, such that computer programs read from theremovable medium 2011 are installed on the storage section 2008 asneeded.

In a case of performing the series of processing described above bysoftware, programs consisting of the software are installed from thenetwork for example the Internet or the storage medium for example theremovable medium 2011.

Those skilled in the art should understand that the storage medium isnot limited to the removable medium 2011 shown in FIG. 20 which storesprograms and is distributed separately from the device to provide theprograms to the user. Examples of the removable medium 2011 include: amagnetic disk (including a floppy disk (registered trademark), anoptical disk (including a compact disk read only memory (CD-ROM) and adigital versatile disk (DVD), a magnetic-optical disk (including a minidisk (MD) (registered trademark)), and a semiconductor memory.Alternatively, the storage medium may be a hard disk included in the ROM2002 and the storage section 2008 which stores programs. The storagemedium and the device including thereof together are distributed to theuser.

A program product storing machine readable instruction codes is furtherprovided according to the embodiments of the present disclosure. Whenread and executed by a machine, the instruction codes cause the machineto perform the method according to the embodiment of the presentdisclosure.

Accordingly, a storage medium for carrying the program product storingthe machine readable instruction codes is also included in the presentdisclosure. The storage medium includes but not limited to a floppydisk, an optical disk, a magnetic-optical disk, a storage card and amemory stick and so on.

The embodiments of the present disclosure further relate to anelectronic device in the following. In a case that the electronic deviceis for base station side, the electronic device may be implemented asany type of evolved node B (eNB), such as a macro eNB and a small eNB.The small eNB may be an eNB covering a cell smaller than a macro cell,such as a pico eNB, a micro eNB and a home (femto) eNB. Alternatively,the electronic device may be implemented as any other type of basestations, such as a NodeB and a base transceiver station (BTS). Theelectronic device may include: a body configured to control wirelesscommunication (also referred to as a base station device); and one ormore remote radio heads (RRH) located at positions different from thebody. In addition, various types of terminals described in the followingeach may function as a base station to operate by performing functionsof the base station temporarily or in a semi-permanent manner.

In a case that the electronic device is for user equipment side, theelectronic device may be implemented as a mobile terminal (such as asmart phone, a tablet personal computer (PC), a notebook PC, a portablegame terminal, a portable/dongle mobile router and a digital camera) ora vehicle terminal (such as an automobile navigation device). Inaddition, the electronic device may be a wireless communication moduleinstalled on each of the above terminals (such as an integrated circuitmodule including one or more chips).

[Application Example On Terminal Device]

(First Application Example)

FIG. 21 is a block diagram illustrating an example of a schematicconfiguration of a smart phone 2500 to which the technology of thepresent disclosure may be applied. The smart phone 2500 includes aprocessor 2501, a memory 2502, a storage 2503, an external connectioninterface 2504, a camera 2506, a sensor 2507, a microphone 2508, aninput apparatus 2509, a display apparatus 2510, a speaker 2511, a radiocommunication interface 2512, one or more antenna switches 2515, one ormore antennas 2516, a bus 2517, a battery 2518, and an auxiliarycontroller 2519.

The processor 2501 may be, for example, a CPU or a system on a chip(SoC), and controls functions of an application layer and another layerof the smart phone 2500. The memory 2502 includes RAM and ROM, andstores a program that is executed by the processor 2501, and data. Thestorage 2503 may include a storage medium such as a semiconductor memoryand a hard disk. The external connection interface 2504 is an interfacefor connecting an external apparatus such as a memory card and auniversal serial bus (USB) apparatus to the smart phone 2500.

The camera 2506 includes an image sensor such as a charge coupled device(CCD) and a complementary metal oxide semiconductor (CMOS), andgenerates a captured image. The sensor 2507 may include a group ofsensors such as a measurement sensor, a gyro sensor, a geomagneticsensor, and an acceleration sensor. The microphone 2508 converts soundsthat are input to the smart phone 2500 to audio signals. The inputdevice 2509 includes, for example, a touch sensor configured to detecttouch onto a screen of the display apparatus 2510, a keypad, a keyboard,a button, or a switch, and receive an operation or information inputfrom a user. The display apparatus 2510 includes a screen such as aliquid crystal display (LCD) and an organic light-emitting diode (OLED)display, and displays an output image of the smart phone 2500. Thespeaker 2511 converts audio signals that are output from the smart phone2500 to sounds.

The radio communication interface 2512 supports any cellularcommunication scheme such as LTE and LTE-Advanced, and performs radiocommunication. The radio communication interface 2512 may typicallyinclude, for example, a BB processor 2513 and an RF circuit 2514. The BBprocessor 2513 may perform, for example, encoding/decoding,modulating/demodulating, and multiplexing/demultiplexing, and performsvarious types of signal processing for radio communication. Meanwhile,the RF circuit 2514 may include, for example, a mixer, a filter, and anamplifier, and transmits and receives radio signals via the antenna2516. The radio communication interface 2512 may be a chip module havingthe BB processor 2513 and the RF circuit 2514 integrated thereon. Theradio communication interface 2512 may include multiple BB processors2513 and multiple RF circuits 2514, as illustrated in FIG. 21. AlthoughFIG. 21 illustrates the example in which the radio communicationinterface 2512 includes the multiple BB processors 2513 and the multipleRF circuits 2514, the radio communication interface 2512 may alsoinclude a single BB processor 2513 or a single RF circuit 2514.

Furthermore, in addition to a cellular communication scheme, the radiocommunication interface 2512 may support another type of radiocommunication scheme such as a short-distance radio communicationscheme, a near field communication scheme, and a radio local areanetwork (LAN) scheme. In this case, the radio communication interface2512 may include the BB processor 2513 and the RF circuit 2514 for eachradio communication scheme.

Each of the antenna switches 2515 switches connection destinations ofthe antennas 2516 among multiple circuits (such as circuits fordifferent radio communication schemes) included in the radiocommunication interface 2512.

Each of the antennas 2516 includes a single or multiple antenna elements(such as multiple antenna elements included in an MIMO antenna), and isused for the radio communication interface 2512 to transmit and receiveradio signals. The smart phone 2500 may include the multiple antennas2516, as illustrated in FIG. 21. Although FIG. 21 illustrates theexample in which the smart phone 2500 includes the multiple antennas2516, the smart phone 2500 may also include a single antenna 2516.

Furthermore, the smart phone 2500 may include the antenna 2516 for eachradio communication scheme. In this case, the antenna switches 2515 maybe omitted from the configuration of the smart phone 2500.

The bus 2517 connects the processor 2501, the memory 2502, the storage2503, the external connection interface 2504, the camera 2506, thesensor 2507, the microphone 2508, the input device 2509, the displaydevice 2510, the speaker 2511, the radio communication interface 2512,and the auxiliary controller 2519 to each other. The battery 2518supplies power to blocks of the smart phone 2500 illustrated in FIG. 21via feeder lines, which are partially shown as dashed lines in thefigure. The auxiliary controller 2519 operates a minimum necessaryfunction of the smart phone 2500, for example, in a sleep mode.

(Second Application Example)

FIG. 22 is a block diagram of an example of a schematic configuration ofan automobile navigation device 2620 to which the technology of thepresent disclosure may be applied. The automobile navigation device 2620includes: a processor 2621, a memory 2622, a global positioning system(GPS) module 2624, a sensor 2625, a data interface 2626, a contentplayer 2627, a storage medium interface 2628, an input apparatus 2629, adisplay apparatus 2630, a speaker 2631, a radio communication interface2633, one ore more antenna switches 2636, one or more antennas 2637 anda battery 2638.

The processor 2621 may be for example a CPU or a SoC, and controls anavigation function and other functions of the automobile navigationdevice 2620. The memory 2622 includes RAM and ROM, and stores programexecuted by the processor 2621 and data.

The GPS module 2624 measures a position of the automobile navigationdevice 2620 (such as a latitude, a longitude and a height) using a GPSsignal received from a GPS satellite. The sensor 2625 may include agroup of sensors, such as a gyro sensor, a geomagnetic sensor and an airpressure sensor. The data interface 2626 is connected to a vehiclenetwork 2641 via a terminal not shown, and acquires data generated bythe vehicle (such as vehicle speed data).

The content player 2627 reproduces content stored in a storage medium(such as CD and DVD) inserted into the storage medium interface 2628.The input apparatus 2629 includes a touch sensor, a button or a switchconfigured to detect touch onto a screen of the display apparatus 2630,and receive an operation or information input by a user. The displayapparatus 2630 includes a screen such as an LCD or an OLED display, anddisplays an image with a navigation function or reproduced content. Thespeaker 2631 outputs sounds of a navigation function or reproducedcontent.

The radio communication interface 2633 supports any cellularcommunication scheme (such as LTE and LTE-advanced) and performs radiocommunication. The radio communication interface 2633 may generallyinclude for example a BB processor 2634 and an RF circuit 2635. The BBprocessor 2634 may perform for example encoding/decoding,modulating/demodulating and multiplexing/demultiplexing, and performsvarious types of signal processing for radio communication. In addition,the RF circuit 2635 may include for example a mixer, a filter and anamplifier, and transmits and receives a radio signal via the antenna2637. The radio communication interface 2633 may be a chip module havinga BB processor 2634 and an RF circuit 2635 integrated thereon. As shownin FIG. 22, the radio communication interface 2633 may include multipleBB processors 2634 and multiple RF circuits 2635. Although FIG. 22 showsthe example in which the radio communication interface 2633 includesmultiple BB processors 2634 and multiple RF circuits 2635, the radiocommunication interface 2633 may also include a single BB processor 2634or a single RF circuit 2635.

Further, in addition to the cellular communication scheme, the radiocommunication interface 2633 may support other types of radiocommunication schemes, such as a short distance radio communicationscheme, a near field communication scheme and a wireless LAN scheme. Inthis case, for each radio communication scheme, the radio communicationinterface 2633 may include the BB processor 2634 and the RF circuit2635.

Each of the antenna switches 2636 switches connection destinations ofthe antennas 2637 among multiple circuits (such as circuits fordifferent radio communication schemes) included in the radiocommunication interface 2633.

Each of the antennas 2637 includes a single or multiple antenna elements(such as multiple antenna elements included in an MIMO antenna) and isused for the radio communication interface 2633 to transmit and receivea radio signal. As shown in FIG. 22, the automobile navigation device2620 may include multiple antennas 2637. Although FIG. 22 shows theexample in which the automobile navigation device 2620 includes multipleantennas 2637, the automobile navigation device 2620 may include asingle antenna 2637.

In addition, the automobile navigation device 2620 may include anantenna 2637 for each radio communication scheme. In this case, theantenna switch 2636 may be omitted from the configuration of theautomobile navigation device 2620.

The battery 2638 supplies power for blocks of the automobile navigationdevice 2620 shown in FIG. 22 via feeder lines, which are shown partiallyas dotted lines in the figure. The battery 2638 accumulates the powerprovided by the vehicle.

The technology of the present disclosure may also be implemented as avehicle system (or a vehicle) 2640 including one or more of theautomobile navigation device 2620, the vehicle network 2641 and thevehicle module 2642. The vehicle module 2642 generates vehicle data(such as a vehicle speed, an engine speed and fault information), andoutputs the generated data to the vehicle network 2641.

In the description of specific embodiments of the present disclosureabove, features described and/or illustrated for one embodiment may beused in one or more other embodiments in the same or similar manner,combined with features in other embodiments, or substitute for featuresin other embodiments.

It should be noted that, terms “including/comprising” used herein referto existing of features, elements, steps or components, but existing oradding of one or more other features, elements, steps or components isnot excluded.

In the above embodiments and examples, reference numerals consisting ofnumbers are used to indicate various steps and/or units. Those skilledin the art should understand that the reference numerals are used tofacilitate describing and drawing, and are not intended to indicate anorder or limit in any way.

In addition, the method according to the present disclosure is notlimited to be performed in a time order described in the description,and may be performed according to other time orders, in parallel orindependently. Therefore, the order in which the method described in thedescription is performed does not limit the technical scope of thepresent disclosure.

Although the present disclosure is disclosed by the description ofspecific embodiments of the present disclosure above, it should beunderstood that all the embodiments and examples described above areonly schematic and are not intended to limit. For those skilled in theart, various changes, improvements or equivalents may be designed forthe present disclosure within the spirit and scope of the appendedclaims. The changes, improvements or equivalents should be regarded asfalling within the protection scope of the present disclosure.

The invention claimed is:
 1. A communication device for user side,comprising: processing circuitry configured to transmit, based on atransmitting request received from a user equipment or a networkinfrastructure, a reference signal to a master device for determining adistribution of the communication device in a dynamic network in a casewhere the communication device does not serve as a slave device, acquirea density of slave devices in a signal coverage of the master devicebased on one or more of a position and tranmission power of the masterdevice reported to the network infrastructure, wherein the master deviceis configured to determine an operation parameter of the master deviceaccording to a predetermined relation between a density of slave devicesand a network performance, the operation parameter comprising one ormore of a transmission power of the master device and maximum number ofslave devices served by the master device.
 2. The communication deviceaccording to claim 1, wherein the processing circuitry is furtherconfigured to receive the transmitting request via a physical downlinkcontrol channel or a media access control element.
 3. The communicationdevice according to claim 1, wherein in a case where a timeconfiguration for transmitting the reference signal is indicated in thetransmitting request, the processing circuitry is further configured totransmit the reference signal according to the indicated timeconfiguration.
 4. The communication device according to claim 1, whereinthe processing circuitry is further configured to receive, from the userequipment, a broadcast signal comprising the transmitting request, andtransmit the reference signal only in a case where a strength of thereceived broadcast signal comprising the transmitting request is higherthan a predetermined level.
 5. The communication device according toclaim 1, wherein the reference signal includes identificationinformation of the communication device.
 6. A communication methodperformed by a communication device, comprising: transmitting, based ona transmitting request received from a user equipment or a networkinfrastructure, a reference signal to a master device for determining adistribution of the communication device in a dynamic network in a casewhere the communication device does not serve as a slave device, acquirea density of slave devices in a signal coverage of the master devicebased on one or more of a position and transmission power of the masterdevice reported to the network infrastructure, wherein the master deviceis configured to determine an operation parameter of the master deviceaccording to a predetermined relation between a density of slave devicesand a network performance, the operation parameter comprising one ormore of a transmission power of the master device and maximum number ofslave devices served by the master device.
 7. The communication methodof claim 6, further comprising: receiving the transmitting request via aphysical downlink control channel or a media access control element. 8.The communication method of claim 6, in a case where a timeconfiguration for transmitting the reference signal is indicated in thetransmitting request, further comprising: transmitting the referencesignal according to the indicated time configuration.
 9. Thecommunication method of claim 6, further comprising: receiving, from theuser equipment, a broadcast signal comprising the transmitting request;and transmitting the reference signal only in a case where a strength ofthe received broadcast signal comprising the transmitting request ishigher than a predetermined level.
 10. The communication method of claim6, wherein the reference signal includes identification information ofthe communication device.
 11. A vehicle system, comprising: a vehiclenavigation device including processing circuitry, wherein the processingcircuitry is configured to acquire a density of slave devices in asignal coverage of the master device based on one or more of a positionand transmission power of the master device reported to the networkinfrastructure, transmit, based on a transmitting request received froma user equipment or a network infrastructure, a reference signal to amaster device for determining a distribution of the communication devicein a dynamic network in a case where the communication device does notserve as a slave device, wherein the master device is configured todetermine an operation parameter of the master device according to apredetermined relation between a density of slave devices and a networkperformance, the operation parameter comprising one or more of atransmission power of the master device and maximum number of slavedevices served by the master device.
 12. The vehicle system according toclaim 11, wherein the processing circuitry is further configured toreceive the transmitting request via a physical downlink control channelor a media access control element.
 13. The vehicle system according toclaim 11, wherein in a case where a time configuration for transmittingthe reference signal is indicated in the transmitting request, theprocessing circuitry is further configured to transmit the referencesignal according to the indicated time configuration.
 14. The vehiclesystem according to claim 11, wherein the processing circuitry isfurther configured to receive, from the user equipment, a broadcastsignal comprising the transmitting request, and transmit the referencesignal only in a case where a strength of the received broadcast signalcomprising the transmitting request is higher than a predeterminedlevel.